Answer: You can collect seeds for eating or for saving when the sunflower is mature. This takes about 80 days from start to finish. The seedhead will be mature when it bends down and turns a yellowish-brown. When that happens, cut the seedhead off the stalk and put it in a brown paper bag in a cool place. The bag will keep insects from attacking the drying seeds. When the seeds are dry (in about 2-weeks) you can collect them. I just rub the top of the seedhead and the seeds pop out. Save the seeds in an airtight container in a cool, dark place until the next spring. When the soil is warm (April or May in your gardening region), plant the seeds about one inch deep and 12" apart directly outdoors (they don't transplant well). Keep the soil moist and the seeds should germinate in about 2 weeks. Once the plant grows and the seedhead matures, you can cut it off and proceed as above.
Best wishes with your mammoths!
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